System and method for reducing current harmonic distortion in a motor controller

A current regulator for a motor controller reduces distortion of the current output to a motor. Feedback signals corresponding to the current present on the motor are transformed into a fundamental and a harmonic reference frame. Notch filters in each reference frame attenuate components of the current feedback signal from the other reference frame. Current regulators in each reference frame receive the filtered current feedback signal in the corresponding reference frame and generate an output signal that is used to regulate the output current to the motor to the desired level of current in the corresponding reference frame. The output signal from the regulator in the harmonic reference frame is transformed to the fundamental reference frame, and the output of the two regulators are combined in a common reference frame to generate a reference signal corresponding to the required voltage output to the motor to achieve desired operation.